Net Zero News: Daylight Savings Time saves energy

One of the biggest reasons clocks are changed for Daylight Saving Time is that it saves energy. Energy use and the demand for electricity for lighting homes is directly connected to when people go to bed and when they get up. Bedtime for most is late evening through the year. When people go to bed, they turn off the lights and TV. In the average home, 25 percent of all the electricity used is for lighting and small appliances, such as TVs, VCRs and stereos. A good percentage of energy consumed by lighting and appliances occurs in the evening when families are home. By moving the clock ahead one hour, people can cut the amount of electricity consumed each day.

Studies conducted in the 1970s by the U.S. Department of Transportation, showed that the entire country’s electricity usage is trimmed by about one percent each day with Daylight Saving Time, because the time change “makes” the sun “set” one hour later and therefore reduces the period between sunset and bedtime by one hour. This means that less electricity would be used for lighting and appliances late in the day. While the amounts of energy saved per household are small, added up they can be very large.

People also use less electricity because they are home fewer hours during the “longer” days of spring and summer. Most people plan outdoor activities in the extra daylight hours. When people are not at home, they don’t turn on the appliances and lights. In the winter, the afternoon Daylight Saving Time advantage is offset by the morning’s need for more lighting. In spring and fall, the advantage is less than one hour. So, Daylight Saving Time saves energy for lighting in all seasons of the year except for the four darkest months of the year (November-February) when the afternoon advantage is offset by the need for lighting because of late sunrise.